Trac #27823: spkg-configure.m4 for iconv

In general the iconv SPKG is not even required.  It's not installed (or
rather, a dummy empty package is installed) for any platforms except
Cygwin, HP-UX, and Solaris.

The requirement for it on Cygwin is probably outdated--iconv is a
standard library on almost all Cygwin installations, and is surely more
up-to-date than when this SPKG was first added in #8567.  Support for
the other two platforms has not been maintained much.

We can add a configure-time check for it, and treat it as a dummy
package in most cases.

URL: https://trac.sagemath.org/27823
Reported by: embray
Ticket author(s): Dima Pasechnik, Erik Bray
Reviewer(s): Erik Bray, Dima Pasechnik

bootstrap

@@ -29,6 +29,49 @@ PKG=build/pkgs/configure
 MAKE="${MAKE:-make}"
 CONFVERSION=$(cat $PKG/package-version.txt)
 
+install_config_rpath() {
+    # The file config.rpath which comes from gettext is supposed to be
+    # installed by automake, but due to a bug in most distros it is not;
+    # see https://trac.sagemath.org/ticket/27823#comment:17
+    #
+    # Here we need to determine where gettext stores its data files and
+    # copy config.rpath from there to config/
+    gettextize="$(command -v gettextize)"
+    if [ -z "$gettextize" ]; then
+        echo >&2 "gettext and the gettextize program must be installed and be in"
+        echo >&2 "your PATH. E.g. Homebrew installs them in /usr/local/opt/gettext/bin."
+        return 179
+    fi
+    eval `sed -n '/^prefix=.*$/p' $gettextize`
+    eval `sed -n '/^datarootdir=.*$/p' $gettextize`
+    eval `sed -n '/^: \${gettext_datadir=.*$/p' $gettextize`
+
+    if [ -z "$gettext_datadir" ]; then
+        eval `sed -n '/^gettext_dir=.*$/p' $gettextize`
+        # In older versions (before 2014) this is spelled gettext_dir
+        # See https://github.com/autotools-mirror/gettext/commit/ff18897068486560e2bb421004cfbd42b7cdd0f8
+        gettext_datadir="$gettext_dir"
+    fi
+
+    if [ -z "$gettext_datadir" ]; then
+        echo >&2 "Failed to read the gettext_datadir directory from $gettextize"
+        echo >&2 "The config.rpath file must manually be copied into config/"
+        echo >&2 "This file is installed with gettext typically in /usr/share/gettext"
+        return 179
+    fi
+
+    config_rpath="$gettext_datadir/config.rpath"
+    if [ ! -f "$config_rpath" ]; then
+        echo >&2 "Missing $config_rpath file; this indicates a broken gettext install."
+        return 179
+    fi
+
+    echo "bootstrap:$LINENO: installing 'config/config.rpath'"
+    cp "$config_rpath" config/
+}
+
+
+
 bootstrap () {
     rm -f m4/sage_spkg_configures.m4
     spkg_configures=""
@@ -40,6 +83,7 @@ SAGE_SPKG_CONFIGURE_$(echo ${pkgname} | tr '[a-z]' '[A-Z]')"
     done
     echo "$spkg_configures" >> m4/sage_spkg_configures.m4
 
+    install_config_rpath && \
     aclocal -I m4 && \
     automake --add-missing --copy build/make/Makefile-auto && \
     autoconf
@@ -48,7 +92,7 @@ SAGE_SPKG_CONFIGURE_$(echo ${pkgname} | tr '[a-z]' '[A-Z]')"
     case $st in
         0) true;; # Success
 
-        16|63|127)  # no m4 for pkg-config, or autotools not installed, or version too old
+        179|16|63|127)  # install_config_rpath failed|no m4 for pkg-config|autotools not installed|or version too old
             if [ $DOWNLOAD = yes ]; then
                 echo >&2 "Bootstrap failed, downloading required files instead."
                 bootstrap-download || exit $?

build/pkgs/iconv/spkg-configure.m4

@@ -0,0 +1,7 @@
+SAGE_SPKG_CONFIGURE([iconv], [
+    AM_ICONV
+    if test x$am_cv_func_iconv != xyes; then
+       sage_spkg_install_iconv=yes
+    fi
+])
+